With all the sea urchins and whatnot, I'm sure nothing's smelling too floral there. And really, depending what Dharma's putting in that food to keep it so well preserved, I don't think anybody's smelling too good.

The one I'd like to use the toilet after the most, though, would be Paulo. Doesn't leave a smell at all, and you might just get a bit richer.

I have an image of Locke squatting over a hole in the gorund that he has lovingly dug and sculpted to just the right size and depth, with a big leaf in hand ready to wipe, turning his nose up at the smell but being a man and dealing with it

Tom / Mr. Friendly. Logic? Not sure, he just strikes me that way. Well, that and he admittedly dines on extravigant crap when he visits the real world. That's one crazy quantum-flux-dump when he gets back to the island.